(a) Field of the Invention
The present invention relates to an engine for a vehicle, and more particularly, to an intake valve supplying an intake gas to a combustion chamber of the engine.
(b) Description of the Related Art
Generally, an internal combustion engine refers to an engine where a fuel gas generated by combusting fuel directly is applied to a piston, a turbine blade, or the like to convert heat energy of the fuel into mechanical work.
In many cases, the internal combustion engine refers to a reciprocal motion type engine which ignites a mixture gas of the fuel and air in a cylinder to cause an explosion and thus moves a piston, but a gas turbine, a jet engine, a rocket engine, and the like can also be the internal combustion engine.
The internal combustion engine is classified into a gas (or gasoline) engine, a petroleum engine, a diesel engine, and the like depending on the fuel that is consumed. In particular, petroleum, gas, and gasoline engines cause ignition as an electric flame by a spark plug, and the diesel engine sprays the fuel into air at high temperatures and high pressure to cause spontaneous ignition. The engine may utilize a four stroke cycle method or a two stroke cycle method according to a stroke and an operation of the piston.
Typically, it is known that the internal combustion engine of a vehicle has heat efficiency of about 15% to 35%, but about 60% or more of total heat energy is consumed due to heat energy and an exhaust gas emitted to the outside through a wall of the internal combustion engine, even at maximum efficiency of the internal combustion engine.
As described above, if a quantity of heat energy emitted to the outside through the wall of the internal combustion engine is reduced, efficiency of the internal combustion engine may be increased, and therefore methods of installing an adiabatic material outside of the internal combustion engine, changing a portion of a material or a structure of the internal combustion engine, or developing a cooling system of the internal combustion engine are used.
Particularly, if emission of heat generated in the internal combustion engine along the wall of the internal combustion engine to the outside is minimized, efficiency of the internal combustion engine and fuel efficiency of the vehicle may be improved, but research on an adiabatic material, an adiabatic structure, or the like, which may be maintained over a long period of time in the internal combustion engine to which a repeated high temperature and high pressure condition is applied, has not been fully developed.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.